Warning signal



T. J. SCOFIELD Jan. 14, 1941.

WARNING SIGNAL Filed June 11, 1938 InvEn'r n R 7250mm J, 5001mm A'r'rnRuEY PM Jan. 14,1041

PATENT OFFICE mam WARNING SIGNAL Emmi-Winchell,

The smwi .flieh acsrpsratisnsiohio m. assignor to Company, Jackson,

Application June 11, 1038, Serial No. 213,236

iclaiins.

This invention relates to improvements in a warning signal for motor vehicles. More particularly, the invention pertains to an audible signal wherein a vibratory diaphragm is actuated s by an electro-magnetic motor.

The primary object of the invention is in produce a signalling apparatus of the above mentioned class which is of improved simplified construction, whereby the apparatus may be more 10 economically manufactured without impairing or i decreasing the life or the eiiiciency of the apparatus.

In warning signals of the electro-magnetic diaphragm type, the field coil of the electro-mag is net is usually mounted in a case or frame secured to one of a pair of housing sections which support the diaphragm and motor in cooperative relation with each other.

A more specific object of the invention is to 20 utilize portions of the housing section supporting the motor, by stamping or pressing upwardly or outwardly spaced sections thereof, to form a cage integral with said housing section for the field coil of the electro-magnetic motor.

In audible signals of the electro-magnetic diaphragm type, the diaphragm housing section which is utilized to support the motor is usually provided with a plurality of apertures to form air passages extending therethrough in communi- 30 cation with the adjacent side of the diaphragm chamber formed by the housing sections. I

A further object of the invention is to utilize the material punched from the openings formed in the housing section for the air passages in said 35 housing section communicating with the, diaphragm chamber to form the cage for the field coil of the motor.

I obtain these and other objects by mechanism illustrated in the accompanying drawing, in

' 40 which:

Figure 1 is a plan view or a horn or warning signal embodying the various features oi this invention, the cover being removed. I

Figure 2 is a detail transverse sectional view 5 taken substantially in the plane of the line 2-2,

Figure 1, with a rtion oi the cover shown operatively associate with the diaphragm housing sections.

Figure 3 is'a perspective view oi one of the 50 diaphragm housing sections illustrating a field coil cage formed from a portion thereof in accordance with this invention.

The signalling device, as shown more particularly in Figures -1 and 2 oi the drawing, com- 65 prises two circular diaphragm case or housing sections II and II having a diaphragm I! clamped between them by bolts or screws it passing through aligning holes provided in the mar-' ginal portions of the housing sections II and Ii and diaphragm II. A ring gasket i4, composed I oi fibre or other suitable material, may. as shown in Figure 2, be interposed between the marginal portions of the outer diaphragm housing section II and the diaphragm l2;

Thue diaphragm housing sections are, as shown, .composed oi sheet metal plates having their central portions i0 and ii pressed laterally in opposite directions and arranged in opposed relation to each other to form a diaphragm chamber it between said sections. The front diaphragm housing section II is provided with a centrally disposed forwardly extending annular flange I! to which may be secured,'in any suitable manner, .a horn proper or projector (not shown).

The rear'diaphragm housing section I I constitutes a mounting plate for an electric motor for operating the diaphragm II. For this pur pose, the housing section II has the central portion ii thereof provided with an opening I. arranged substantially centrally thereof. A hollow or an apertured core I! is secured, as by electric welding, to the housing section II to extend outwardly orrearwardly from the central portion I! in substantially coaxial relation with the opening II. The numeral 20 indicates the usual preiormed'fleld coil which is releasably secured in position on the core is and in the housing section H by a pair oi metal straps 2i which extend from across the outer or rear face of the coil inwardly or forwardly intermediate the coil and the core I i at substantially diametrlcal opposite sides of the opening ll, said straps having the inner ends thereof bent laterally into engagement with the outer or rear surface of the plate Ii and secured thereto by rivets, electric welding or the like.

The diaphragm i2 is provided with a central opening in alignment with the opening it in the rear housing section ii for the reception of one 5 end of a stud it which is fixedly secured to said diaphragm in any suitable manner as by washers 25 and a nut 28 mounted on said end of the stud in the manner illustrated in Figure 2. The stud 24 extends rearwardly from the diaphragm through opening I. and the interior of the core I! and has the outer end portion thereof provided with screw-threads 21 for the reception of an armature 2' which is screw-threaded on said stud portion. The armature it, in this inu stance, is a cylindrical disk of greater diameter thanthatofthefieldooilllandisadiustably secured to the stud 24 by a lock nut 20 screwthreaded on the outer or rear end portion 21 of the stud.

The armature II and the outer or rear end portion of the stud 24 may be maintained, as shown, against lateral vibratory movement by a resilient support ll carried by the housing II and which comprises a flat spring ll having one end clamped to the stud 24 by the nut 28 and armature 2|. Washers 32 and 32 may, as shown in Figure 2, be positioned at opposite sides of the spring Ii between said spring and the nut 2! and armature 28, respectively.

The numeral 85 designates an automatic circuit breaker or interrupter which is provided, as is usual with motors of this type, to effect intermittent energizing'and de-energizing of the coil 2| in synchronism with the movement of the diaphragm away from and toward the core I. This circuit breaker may be of any suitable construction and, as illustrated, comprises a pair of contact arms 36 and 31 mounted on a bracket 38 secured to the rear diaphragm housing section I I.

Numeral l designates a condenser or resistance also mounted on the housing section I and which is connected in the circuit for the motor so as to be shunted across the contact arms 38 and 37 ina manner and for a p p se well understood by persons familiar with this art.

The housing section II is provided, during the formation thereof, with stamped up portions 42 arranged about the central opening it in substantially concentric relation therewith to provide a cage or frame for the field coil 20. These portions 42 are substantially rectangular platelike members out substantially radially about the opening II in substantially uniform circumferential spaced relation to each other. The plate portions 42 have the inner ends thereof maintained integral with the housing portion II at the inner end of the openings 48 formed in the housing section when said plates are bent or pressed upwardly. The plates or projections 42 are arranged in such spaced relation to the opening It and to the core I! mounted on the housing section adjacent said opening as to provide ample room for the coil 20 to be mounted within the area defined by said plates or projections. These projections may be formed, as hereinbefore stated, simultaneously with the forming of the central portion H of the plate and the openings 43 produced thereby form air passageways communicating with the adiacent portion of the diaphragm chamber I! provided by the housing sections or plates ll and ii.

aaaac'n Theproiectionsorstampedupportionsll form the external metallic path for the magnetic fiuxofthecoilll andarearrangedwiththe outer ends thereof positioned in substantially the plane of the outer end of core I! which, as illus- 6 trated in Figure 2, is preferably a short distance beyond the outer face of the coil ll.

While the form of embodiment of the present invention, as herein disclosed, constitute a preferred construction, it is understood that other forms or constructions may be adopted, all coming within the scope of the appended claims.

I claim:

1. In an electro-magnetic diaphragm type warning signal having an electro-magnetic motor including an electro-magnetic field coil, a plate. supporting both the diaphragm and said motor on opposite sides thereof, said plate having a hole provided therein to accommodate the connecting means between the motor and the diaphragm, the combination with the electro-magnetic motor field coil, of a plurality of separate holes punched in said plate arranged in circumferential spaced relation to each other about said first mentioned hole to provide air passages through said plate, the material punched from said separate holes remaining fastened to the plate at one edge of the holes and bent upward so as to extend about the first mentioned hole to form a cage surrounding said motor field coil and providing an external magnetic path for the magnetic fiux of said field coil.

2. In a warning signal of the character described including a housing plate constructed of metal of high magnetic permeability and an electro-magnetic motor field coil mounted on said plate, the combination with said coil, of a cage comprising a plurality of prongs punched and bent from said plate to form a cage surrounding said motor and providing an external magnetic path for the magnetic flux of said coil.

3. In an electro-magnetic diaphragm type warning signal having an electro-magnetic motor including an electro-magnetic field coil, a plate supporting both the diaphragm and the electro- 5 magnetic motor on opposite sides thereof, said plate having a hole provided therein to accommodate the connecting means between the motor and the diaphragm, the combination with the electro-magnetic motor field coil, of a plurality w of projections punched and bent from said plate to form a cage surrounding said field coil and thus providing a plurality of high permeability paths for the external magnetic flux of said field coil.

THEODORE J SCOP'IELD. 

